Stage 2
LMS guide
Alternative Power Source: Hydroelecticity | Show Menu |
Dams are usually built on a large drop in a river although they don't necessarily need to be built in a large drop. A dam stores large amounts of water behind a wall in a reservoir. Near the bottom of the wall is the water intake pipe or penstock where water is released from the reservoir further into the penstock, which builds up pressure. The water then continues to flow through the penstock and into the turbine. The water then forces the turbine propeller to turn which then activates the electrical generator. When the water hits the turbine it becomes kinetic energy. Then the water travels back into the river going through the tailrace.
The route the water travels through
When the turbine turns, the excitor sends an electrical current to the rotor. The rotor is a bunch of large electromagnets that spin in a tightly wrapped up coil of copper wire (this is in the stator). The magnetic field between the magnets and coils creates an electric current.
As the water travels through the penstock it will get to the turbine and the water will hit the blades powering up turbine (which is attached to a generator). The most common hydroelectric turbine is the "Francis turbine" which looks like a large disc with curved blades. When the blade turns in the turbine so do a series of magnets inside the generator. Big magnets rotate past rubber coils, producing an AC by moving electrons.
Hydroelectricity is used in 24% of the worlds power.
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Comments:
From judysara - 6/14/05 8:26 PM
From Jsquires - 6/10/05 8:09 AM
more energy words needed
From judysara - 6/7/05 7:08 PM
A diagram with labels is needed.
Navigation back to the home page and to the other page need to be added.
Last Modified 6/10/05 9:08 AM